ASCA observations of deep ROSAT fields - III. The discovery of an obscured Type 2 AGN at z=0.67

We report on the discovery of a narrow-emission-line object at z=0.672 detected in a deep ASCA survey. The object, AXJ0341.4-4453, has a flux in the 2-10 keV band of 1.1+/-0.27x10^-13 erg s^-1 cm^-2, corresponding to a luminosity of 1.8x10^44 erg s^-1 (q_0=0.5, H_0=50 km s^-1 Mpc^-1). It is also marginally detected in the ROSAT 0.5-2 keV band with a flux 5.8x10^-15 erg s^-1 cm^-2. Both the ASCA data alone and the combined ROSAT/ASCA data show a very hard X-ray spectrum, consistent with either a flat power law (alpha<0.1) or photoelectric absorption with a column of n_H>4x10^22 cm^-2 (alpha=1). The optical spectrum shows the high-ionization, narrow emission lines typical of a Seyfert 2 galaxy. We suggest that this object may be typical of the hard sources required to explain the remainder of the X-ray background at hard energies.